Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds genuinely new context: it takes no arguments, kind/prompt merely pre-fill, and the tool returns only a short summary to the agent while the home is rendered for the person — a non-obvious behavior worth stating.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The purpose and scope are front-loaded in the first clause, and each subsequent sentence (usage trigger, arguments, return behavior) adds distinct information. It is slightly dense but nothing is redundant with the schema or annotations.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists so return values need not be enumerated, and annotations cover the safety profile. The description still supplies the important detail that the agent receives only a summary while the person sees the home, leaving little missing for correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3 and the schema carries the parameter documentation. The description still adds meaning by clarifying that both parameters are optional pre-fills of the composer rather than required inputs, which reinforces their optionality and effect.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ("Open Veltake's home for the person") and immediately qualifies it as a composer for images, video, speech and music with coin pricing and recent work. That is far more specific than a tautology, but it never explicitly separates itself from the sibling app_home, which an agent must distinguish between.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives an explicit trigger condition: "Use it when the person wants to browse, pick a model or settings themselves, or start from a workflow." That implicitly contrasts with direct-generation siblings like app_generate, but no alternative is named and no when-not case is stated.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.